A non-hormonal pill can improve the chances of pregnancy and live births for women undergoing assisted reproductive treatments compared with placebo, initial findings from a phase II trial show.
OXO-001 is the first drug of its kind and acts to make the innermost lining of the uterus more conducive to embryo implantation and pregnancy.
The findings from a subset of participants in the OXOART2 trial showed a significant 10.6 percent absolute increase in the primary outcome of ongoing pregnancy when the drug was combined with embryo transfer using a donor egg.
There were also statistically significant 6.9 percent gain in live birth rates compared with placebo using the drug, produced by Spanish biotech Oxolife.
The company’s CEO and founder Agnès Arbat will present the trial findings today at the European Society of Human Reproduction and Embryology 40th annual meeting in Amsterdam.
“Most rounds of IVF or ICSI still end in failure—many, because a viable embryo does not implant,” she said in a press statement.
“A simple-to-take pill that materially improves the chance of success would therefore be of huge benefit to those who want a baby. This proof-of-concept phase II study shows that hope is now a step closer.”
The drug works on the endometrium to encourage the embryo to stop rolling, to access the tissue there and complete implantation. It is taken daily, beginning one menstrual cycle before embryo transfer and then five weeks after this and is rapidly absorbed before being expelled by the body within 24 hours of administration.
It has been tested in 300 women to date and follow up at six months after birth has revealed normal development in all babies, with no differences compared with placebo.
The exploratory subset of the OXOART2 study included 96 women aged up to 40 years old underwent a fresh single blastocyst transfer resulting from donor oocyte using in vitro fertilization or intracytoplasmic sperm injection.
Of these, 54 received daily OXO-001 and 42 received placebo treatment.
Early, biochemical pregnancy rates were significantly greater in the OXO-001 group, at 75.9% versus 52.4% with placebo.
There was also a 14.3% absolute increase in clinical pregnancy rates in which there was a fetal heartbeat five weeks after embryo transfer, with this observed in half the women receiving active treatment versus 35.7% of those receiving placebo.
Ongoing pregnancy rates at 10 weeks after embryo transfer, in which there was a fetal heartbeat confirmed using ultrasound, were 46.3% with OXO-001 compared with 35.7% with placebo treatment.
Live births occurred in a corresponding 42.6% versus 35.7%.
“We are thrilled with the results of this trial, which highlight OXO-001’s potential to become the first therapeutic treatment to increase embryo implantation success, with a non-hormonal drug using a new mechanism of action, acting directly on the endometrium,” said Oxolife chief scientific officer Ignasi Canals, PhD.
Arbat added: “This study was purposefully designed to include only women who used donor eggs so it could single out the true effect of OXO-001 on the endometrium.
“However, we believe OXO-001 has the potential to work equally well in those using their own eggs, and we are already planning a pivotal Phase III clinical trial in this more extensive group to support product registration.”
The study abstract will be published today in the journal Human Reproduction.
